The broad, long-term objective of this research is to reduce the prevalence of at-risk gambling and related harm in the population, through development of efficacious indicated prevention techniques. Gambling represents a rising and often unrecognized public health threat in the US, and the age range from late adolescence to early adulthood is a particular period of vulnerability for excessive gambling. Between 9-15 percent of college students can be characterized as at-risk gamblers, exhibiting some consequences of gambling but not yet meeting DSM-IV criteria for pathological gambling. The primary aim of the current project is to document the efficacy of a 60-90 minute Personal Feedback Intervention (PFI) incorporating Motivational Interviewing and brief skills elements in comparison to a 6-session Cognitive Behavioral (CBT) group intervention and an assessment only condition, in reducing gambling behavior and related negative consequences of at-risk college student gamblers (N=300), identified through brief screening of a random sample of UW freshmen (N=3000) conducted in years 1 & 2 of the grant period. A secondary aim is to evaluate potential moderators and mediators of intervention efficacy. Moderating hypotheses are specified for self-determination, gambling motives, readiness to change, and cognitive distortions. Mediating hypotheses are specified for readiness to change, normative perceptions, cognitive distortions, and coping skills. At-risk gamblers (SOGS score 3 or above but not meeting DSM-IV criteria for pathological gambling) will be assessed at baseline, post-intervention, 6- & 12-months post-baseline. The study addresses several gaps in the gambling literature, including lack of research on indicated prevention, lack of prior efficacy data on PFI interventions for gambling, a lack of interventions targeting the vulnerable college years, and few trials comparing CBT (especially group CBT) to any other active treatment for gambling. In addition, there is virtually no research evaluating mediators or moderators of gambling intervention efficacy.